Merkel defends painful coalition concessions, denies authority waning

BERLIN, Feb 11 (Reuters) - German Chancellor Angela Merkel on Sunday defended "painful" concessions she has made to the Social Democrats (SPD) to secure a fourth term and said growing criticism among her conservatives was not a sign that her authority was waning.

Asked whether she was planning to groom a successor to lead her conservatives in the next election, Merkel said she wanted a younger generation of her Christian Democrats (CDU) to fill ministerial posts in a new coalition with the SPD. (Reporting by Joseph Nasr; editing by Andrew Roche)